Design of layered structure with nanofibrous resonant membrane for acoustic applications

Textiles such as wool felts are very commonly used materials for sound absorbing purposes on commercial white goods (e.g., washing machines, tumble dryers). In this study, it was aimed to discuss the limitations of wool felts for a domestic type washing machine. Accordingly, an alternative sound absorption material in a layered form was designed, in which a nonwoven covering together with nanofibrous resonant membrane and wool felt were used. The nanofibrous membrane in the structures was developed and its properties were discussed within the scope of the previous works of the authors. Therefore, this paper focused on the spunbond and meltblown nonwovens of various areal densities, which were employed as covering materials in the layered structures. The single and multilayered nonwovens were selected regarding three main criteria, namely acoustic performance, cost, and ease of production. The acoustic performance of the layered (combined) structures was measured in accordance with the relevant standards, and the results were comparatively discussed. In addition to that, Technique for Order Preference by Similarity to Ideal Solution together with Analytic Hierarchy Process was employed not only to determine the best performed nonwoven as a covering layer, but also to find out the optimized solution among the combined (layered) structures developed, so far as the acoustic behavior was concerned.